.banner{
    width: 600px;
    height: 400px;
    border: 1px solid #666;
    overflow: hidden;
    position: relative;
    margin: 50px auto;
}
.banner img{
    position: absolute;
}
.banner img:nth-of-type(1){
    z-index: 100;
}
button{
    cursor: pointer;
    width: 40px;
    height: 70px;
    border: none;
    background: url("../images/icon-slides.png");
    position: absolute;
    z-index: 200;
}
.position-center-y{
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
}
.next{
    right: 0;
    background-position-x: -126px;
}
.prev{
    background-position-x: -83px;
}
.prev:hover{
    background-position-x: 0;
}
.next:hover{
    background-position-x: -42px;
}
.all-icons{
    position: absolute;
    z-index: 300;
    left: 50%;
    transform: translateX(-50%);
    bottom: 20px;
}
.all-icons span{
    display: inline-block;
    cursor: pointer;
    margin-right: 5px;
    width: 20px;
    height: 20px;
    border: 1px solid #fff;
    background-color: #A8A09C;
    border-radius: 50%;
}
.all-icons .active{
    background: orangered;
}